A PERSON WHO works as a bartender, waitress, or musician should not be required to pursue his or her profession while breathing a proven carcinogen: secondhand cigarette smoke. That is the sound principle behind the move by health officials in Boston and 11 surrounding communities to ban smoking from bars and clubs.

Bars and clubs, last holdouts against smoking bans, have no more intrinsic right to subject their employees and patrons to this health hazard than restaurants and airlines did until not too many years ago. An attempt last year to pass a statewide ban in bars was blocked in the Legislature by the lobbying power of the Massachusetts Restaurant Association.

This week's initiative by local health officials is more likely to succeed in the affected communities with their combined population of more than 1 million. In recent years, many Massachusetts communities have managed on an individual basis to ban smoking from the eating areas of restaurants despite industry protests. In 1996 Brookline banned it from bars as well with no calamitous effects on business. Also, in Boston and some of the other communities in the Clean Air Works campaign, the decision is in the hands of health board or commission members, who ought to be less easily swayed by lobbyists than legislators.

Local health officials base their case against workplace smoking on studies like the one published last month by the Centers for Disease Control and Prevention, which estimates that heart disease and lung cancer caused by secondhand smoke are responsible for 38,000 deaths in the United States each year. According to a 1993 study by Michael Siegel, now of Boston University, that was published in the Journal of the American Medical Association, bar and restaurant workers are 1.5 to 2 times more likely to die of lung cancer than they would be if bars and restaurants were smoke-free. Both the National Institutes of Health and the Environmental Protection Agency have classified secondhand smoke as a carcinogen.

Making the initiative a regional campaign was a wise decision by its organizers. If all or most of the 12 communities enact bans, individual owners of businesses cannot complain that customers who want to smoke while drinking will simply flock to establishments across a city line. The regional approach has worked well on Cape Cod, where Provincetown just two weeks ago became one of the many Cape communities to enact a ban. Both California and Delaware have enacted statewide bans.

The campaign has won the enthusiastic endorsement of the Boston Hotel Workers Union Local 26, with 5,800 workers in Boston and Cambridge. The union's support draws attention to the fact that the smoking ban is at its heart a workers' rights issue - the right to work in an environment free of a known cause of disease.